Improvement in die-stocks for cutting screws



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No. 136,153., r I 1 UNITED STATES "JOHN ieRAn'r, or cnnnnrrnnn, MASSACHUSETTS.

IMPROVEMENT IN DIE-STOCKS FOR CUTTING SCREWS.

Specification forming part of Letters Patent No. 136,153, dated February 25, 1873.

To all whom it may concern:

Be it known that I, JOHN'J. GRANT, of

Greenfield, county of Franklin, and State of Massachusetts, have invented a certain Improvement in Die-Stocks for Cutting Screws, of which the following description, taken in connection with the accompanying plate of drawing hereinafter referred to, forms a full and exact specification, wherein are set forth the nature and principles of the invention, by which the same may be distinguished. from others of a similar class, together with such parts thereof as are claimed as new and are desired to be secured by Letters Patent of the United States.

My invention relates to an improved meth- 7 od of securing and adjusting the dies in the stock; and the nature thereof consists, first, in providing the plate or stock with a cylindrical receptacle for the reception of the collet containing the die, and so constructing the plate as to form a spring-clamp, which.

may be made tobind the collet firmly in position; second, in combining with a collet or holder, having a guide so constructed as to start the bolts true and insure a correct inclination of the thread, a stock with a cylindrical receptacle for the reception of the collet containing the die, and thereby causing the screw to be cut with dispatch and accuracy.

In die-stocks or hand-plates as heretofore constructed it has been found difficult to at ta-in accuracy of workmanship in cutting screws, the thread being imperfect and the pitch irregular. Practice has fully demonstrated, however, that in die-stocks embody-- ing my improvements these difficulties are entirely obviated, and that the screws produced by the operation thereof have a regularlypitched and sharply-defined thread.

In the accompanying plate of drawing, which illustrates my invention and forms a part of the specification thereof, Figure 1 is a top View of the implement. Fig. 2 represents the stock or plate with the collet containing the die removed therefrom. Fig. 3 is a vertiflal Section. Fig. 4 is a view of the under s1 e,

In thedrawing, A designates theplate or stock, of elastic metal, provided with handles B and a cylindrical socket or receptacle, 0, of

suitable size for the reception of the collet D. Upon the bottom of the said socket is the flange'or rim E, the office of which is to form a support for the said collet. The said plate isdivided into two parts or jaws, H, by the vertical aperture or slit F, which are sprung slightly apart by the force of the elasticity of the metal of which the implement is manufactured. The said collet is secured within the receptacle 0 by introducing it within the same when the jaws are thus parted, and then turning the set-screw I, by which the parts are firmly clamped together. The dies k. are se cured and adjusted within the collet or holder D by means of taper-headed adjusting-screws, operating, in combination with external setscrews, in the manner fully described in the patent granted to me for improvement in dies for cutting screw-threads on the 24th day of October, 1871, and numbered 120,266. The said collet is provided with a guide, m, cast sdlid therewith, and having a cylindrical aperture, n, which is made to vary in diameter, according to the size of the dies made use of. Each of the different-sized dies used will thus have a guide of proper shape attached to it.

Having thus described the construction and operation of my invention, I will indicate in thefollowing clauses what I claim and desire to secure by Letters Patent:

1. The elastic die-stock or plate, with a cylindricalreceptacle or socket divided by a vertical aperture and provided with a set-screw, as and for the purposes described.

2. The combination of the die-stock, constructed as described, and the collet, constructed as described. v

In testimony that I claim the foregoing I have hereunto set my hand this 6th day of November, 1872.

JOHN J. GRANT.

Witnesses:

WENDELL T. DAVIS, HANNAH '1. REED. 

